Question

A ray of light exits from a material with a refractive index of 1.75, traveling into air. The angle of refraction is 25°. What was the original angle of incidence?​

Answer 1

θi = 47.7°

Step-by-step explanation:

The formula for the refractive index is as follows:

`n = (Sin\theta_i)/(Sin\theta_r)`

where,

n = refractive index = 1.75

θi = angle of incidence = ?

θr = angle of refraction = 25°

Therefore,

`1.75 = (Sin\ \theta_i)/(Sin\ 25^o) \\\\(1.75)(Sin\ \ 25^o) = Sin\ \theta_i\\\\\theta_i = Sin^(-1)(0.739)`

θi = 47.7°